压电液压马达的性能分析与测试

Performance analysis of a piezohydraulic motor

为满足大行程、高输出力精密驱动与控制的需求,提出一种压电叠堆隔膜泵驱动的压电液压马达,建立了理论模型并进行了仿真分析.给出了刚度匹配时最佳面积比及最佳负载的确定方法.设计制作了试验样机,测试了半径比对其性能的影响规律.在工作频率为280 Hz时,半径比为0.8马达的输出功率是半径比为0.53马达输出功率的4.43倍,这说明选取合理的结构参数可有效地提高马达性能.理论分析结果表明,负载一定时,存在最佳的结构参数(刚性顶块与泵腔的半径比、泵腔与液压缸面积比)使马达速度及功率最大、最佳面积比随半径比增加而减小.结构参数一定时,速度随负载增加而降低、存在最佳负载使输出功率最大,且最佳负载随面积比及半径比增加而降低.

A novel piezohydraulic motor driven by a piezostack membrane pump was created for applications requiring large forces and displacements with accurate actuation and control.An analytical model was established to help evaluate its performance.The influence of the stiffness of the pump chamber＇s diaphragm on the dynamic-response performance of a piezostack actuator and the relationship between optimal area ratio and load at stiffness-matching point were primary considerations.A piezohydraulic motor was fabricated and tested to compare performance at different radius ratios.At a frequency of 280 Hz,the power produced by the motor at a radius ratio of 0.8 was 4.43 times at the power achieved with a radius ratio of 0.53.The results of the simulation showed that optimal selection of structural parameters can effectively enhance the performance of motor.These included the radius ratio of rigid-disk to pump-chamber and the area ratio of the pump-chamber to the cylinder piston at given external loads.The optimal area ratio decreased with increases in the radius ratio.At a given radius ratio and area ratio,the velocity of the piezohydraulic motor decreased with increases in the external loads.There was an optimal load to achieve maximum power output.Increases in the optimal area ratio and radius ratio led to decreases in the optimal load.